Field
The present disclosure relates to methods of modifying a glass-ceramic article, and more particularly, relates to methods of modifying a non-damaged surface of a glass-ceramic article by applying a chemical etching solution thereto.
Technical Background
The use of glass ceramics in electronic devices is becoming increasingly popular. The use of glass and glass ceramics in electronic devices provides optical properties and surface textures which significantly influence the functionality, touch feeling, and appearance of such devices. In particular, the surface appearance (e.g., gloss value, surface roughness, and anti-glare properties) of glass and glass ceramics has become important in recent years to meet consumer demands.
In order to reduce the glare and/or reflection from the ambient environment on the surface of glass ceramics during the usage, and also to provide smooth tactile feel, several methods may be employed which include: 1) providing an anti-reflection (hereinafter “AR”) coating; and 2) providing an anti-glare (hereinafter “AG”) treatment. AR coatings reduce the refractive index difference between the surface of the glass ceramic and the ambient environment. AG treatment, through roughening of the surface of the glass ceramic, causes the reflection to be scattered into different direction. Typically, to achieve similar performance, AR coatings are more expensive than AG treatment. Additionally, AR coatings are generally smooth, which does not change the tactile response from un-treated surfaces. Surface glare of glass ceramics may also be reduced by roughening of such surfaces, which may be achieved by the following methods: 1) coating; 2) sand blasting; and 3) chemically etching the surface of the glass ceramic. For AG coating, the surface is coated with organic or non-organic droplets or particles. While such coatings can provide scattering properties, they are not normally very durable to scratch.
Currently, in order to reduce the gloss of glass ceramics via roughening, surfaces of glass ceramics are first treated by physically damaging of the surfaces (e.g., sand blasting), followed by chemically etching the surfaces with HF. Physically damaging the surfaces is employed to generate a rough and/or damaged glass ceramic surface, and chemically etching is employed to polish and strengthen the rough and/or damaged glass ceramic surface. The combined processes may produce a glass ceramic surface with gloss values of from 30% to 90%, and with roughness (i.e. Ra) from 0.1 to 20 μm.
However, these processes include several limitations and drawbacks, such as: 1) by requiring two-steps, the process is unable to adjust surface gloss without physically damaging the surface of the glass ceramics and chemical etching is employed only for polishing and strengthening purposes (and not for gloss manipulation); 2) the processes are unable to precisely control the surface properties of the surface of the glass ceramics, such as surface roughness and gloss; and 3) the physical damage to the surface of the glass ceramics caused by sand blasting permanently damages the glass ceramic surface, and significantly reduces the strength of the base material, and the chemical etching treatment may not be able to fully recover such lost strength.
Accordingly, ongoing needs exist for alternative methods for modifying the surface appearance and the touch and feel of glass ceramics.